Now in its 28th year, the San Francisco Ethnic Dance Festival has been extraordinarily successful at doing two things that seem to be at odds: preserving tradition and innovating dance.

For instance, this year's festival will feature Izumi Sato, a Japanese woman who has mastered Bharatanatyam, an Indian dance form that dates back to the 10th century. According to the festival's executive director, Julie Mushet, there are two dozen performers in the Bay Area who have conquered forms that are not in their cultural traditions.

"It can be sort of jarring to people," Mushet says. "It's so interesting -- you can see how that pushes against progressive notions of people in the Bay Area when you see someone who doesn't look like they're supposed to be dancing in that particular form." In addition, Mushet says, the forms themselves get changed through their performance through time, while still forcing people to recognize the power of their original, often ancient, contexts.

But the festival has always broken new ground. When it started, it was the first multicultural dance festival in the country. Mushet says that as a result of the festival's success, the Bay Area became known as a good place for people interested in ethnic dance. Now, she says, it is the premier locale.

"Finally, ethnic dance was presented in a respectful way," Mushet says. "For too long, it was presented poorly and just outdoors. We are committed to giving the 100-plus dance forms, from countries all over the world, the same kind of attention modern dance and ballet receive. We give these forms a good stage, good lighting, and the result is that we have the best ethnic dance community in the world.

"We see that it's treated beautifully, that these dances wouldn't be performed between donkey acts."

The process for choosing the acts has remained constant over the past two decades: a panel of dance pros judge open auditions over four days. This year, more than 100 groups competed to get one of 30 spots. The festival happens over three weekends, 10 groups at a time. Mushet says she is particularly excited about the premiere dances, such as the Ensambles Ballet Folklorico de San Francisco's performance of "Danza de los Negritos," but the festival's setup encourages appreciation for the spectacle as a whole.

"We put it all on one stage," Mushet said. "There's nothing like it in world. Other places, like Houston, have big festivals, but they focus on a particular form. In the S.F. festival, you get a sense of cultures interacting and influencing each other."